The invention relates to a cover arrangement for a housing of a hand-held power tool, for example, a chain saw, a cut-off machine, a trimmer or the like. The cover arrangement comprises a cover and at least one spring clip for securing the cover detachably to another part of the power tool. The spring clip is arranged at a lateral surface of the cover in the area of the edge of the cover correlated with the lateral surface. For clamping the cover relative to the other part, the spring clip is arranged in a clamping direction that is perpendicular to the edge of the cover.
Hand-guided power tools, such as motor chain saws, trimmers, cut-off machines and the like, are used in environments where they are exposed to high loads of dust and dirt. A drive motor of the power tool when configured as an internal combustion engine takes in combustion air through an intake tract. For removing dust from the incoming air, an air filter is provided. Such an air filter is secured in an air filter box that is closed by a detachable lid. The dust load of the air filter requires cleaning or exchange of the air filter from time to time; for this purpose, the cover of the air filter box must be opened. The same applies also to checking and exchanging the spark plug of the internal combustion engine; the spark plug and the cylinder head are both covered by an appropriate cover.
In addition to easy removability and easy attachment of the cover, a safe fixation of the cover in operation of the power tool is desired. The separating location between the cover and the additional part of the power tool to which the cover is attached is subjected to vibrations that cause wear at the separating location and moreover contribute to sound emission.
U.S. Pat. No. 5,899,182 discloses a housing cover arrangement of a hand-held power tool where the cover is connected by a spring clip to the motor housing. The spring clip is arranged at a lateral surface of the cover in the area of the cover edge that is correlated with the lateral surface and clamps the cover relative to the motor housing in a clamping direction that is perpendicular to the edge of the cover. For positionally securing the cover transversely to the clamping direction, a pin is provided whose longitudinal axis extends in the clamping direction. The pin engages a recess. An end face of the sleeve rests under the effect of the clamping force of the spring clip on an annular support plate made from metal. The arrangement as a whole is rigid and stiff. The spring clip is arranged in immediate vicinity of the rigid arrangement of pin and recess. The action of the clamping force is limited to the area immediately adjacent to the pin. Because this area is relatively stiff, the pretension of the spring clip is based solely on the elastic deformability of the spring clip. Wear and position tolerances can lead to undesirable fluctuations with regard to spring pretension. The rigid contact between cover and motor housing leads to sound traveling from the motor into the cover and being radiated away from the cover.